The invention relates to a camshaft adjuster for adjusting the relative angular position of a camshaft relative to a crankshaft of an internal combustion engine.
In DE 102 48 351 A1, a camshaft adjuster for adjusting the relative angular position of a camshaft relative to a crankshaft of an internal combustion engine is disclosed, in which the adjustment is made with a setting shaft, which is driven by a setting assembly. The setting shaft is in driving connection with an adjusting gear, here a speed-increasing triple-shaft gear mechanism constructed as a double planetary gear, by means of a backlash-free, detachable coupling. The use of a swashplate gear or another triple-shaft gear mechanism is also possible. Through the separate construction of the setting assembly on one side and the adjusting gear on the other side, the setting assembly can be completely preassembled and installed or exchanged based on the detachable coupling in a simple way. As possible couplings, feather key couplings, profiled shaft couplings, such as polygonal, toothed, wedge, and multiple-cornered couplings are noted. As means preventing possible backlash, biased metal or plastic springs, a polymer band, or a polymer O-ring can be used, which are to bridge play between individual coupling surfaces. Furthermore, despite the backlash-free coupling, it is ensured that the axial movement of one coupling half is enabled relative to the other coupling half, so that expansion of the components due to heat is not impaired. The coupling can be constructed as a claw coupling, which has intermeshing axial claws, wherein spacings are provided between the claws, which are bridged without backlash by teeth elements of an elastic, biased polymer collar. The claw coupling also allows the compensation of a small axial offset and also has a vibration-damping effect due to the elasticity of the polymer band. Furthermore, it is proposed that an inner or outer part of the coupling is formed from an elastic plastic. For economical production and for compact construction, it is also proposed that internal or external teeth formed of plastic with a metallic intermediate lining with a corresponding construction is vulcanized or injection-molded onto corresponding parts of the toothed shaft coupling and that the intermediate lining is connected to the toothed shaft coupling preferably by an interference fit.